Ubiquitous expression of
PCAT1–4 mRNAs. (A) Northern blot using
total RNA isolated from A.thaliana seedling, stem,
rosette or flower tissue. The blot was probed with a PCAT2 fragment
and shows two hybridizing bands of ~5.5 and 7.3 kb. Both mRNAs are
of sufficient length to harbor the complete PCAT2 protein coding
region, which is 4.7 kb in length. The 5.5 kb band is marked by
an arrow because it is likely to represent the mature form of the
PCAT2 transcript. The panel at the bottom shows the hybridization
signal of the 25S ribosomal RNA serving as a loading control. (B) PCAT1, 2, 3 and 4 transcripts are expressed in early stages of development (seedlings) and in the three major
tissues (rosette, stem and flowers) of the adult plant. Fragments
of each of the four PCAT transcripts (see Table 1 for location of
amplified fragments) were amplified by RT–PCR from total
RNA isolated from the indicated tissue. Amplification was stopped
while it was still in the linear range. Signals should not be taken
to reflect the precise relative or absolute levels of mRNA abundance.